Snowflakes are like fingerprints; as the saying goes, no two are alike. But how is it possible that every snowflake is unique when so many exist?
It may seem like this is a myth that would be easy to bust, but it actually is true. No two snowflakes are alike. Or at least they probably aren't. About 1 septillion snowflakes fall each winter. Because of the sheer number of them, it would be nearly impossible to prove that no two are identical.
You’ve heard of a million, even a billion. But what's a septillion? It's a 1 followed by 24 zeros. Another way to think of it is that 1 septillion is the equivalent of a trillion trillion. No matter how you look at it, that's a lot of snowflakes. However, because of how they form and are influenced by atmospheric conditions, scientists agree it is highly unlikely identical snowflakes exist.
Snowflakes start to form when water vapor condenses around a tiny particle of dust high above Earth, as far as 6 miles above the ground. These newly evolved particles then crystallize. These snowflakes or snow crystals are very sensitive to their environments, which influences their appearance.
One factor impacting the shape and appearance of snowflakes is temperature. At temperatures between 27 degrees Fahrenheit and 32 degrees Fahrenheit, snowflakes are formed like six-sided plates. When it's a few degrees colder, the flakes have a needle form. At even colder temperatures, snowflakes take on a column form, and then a fernlike star shape at even colder temperatures.
Humidity also plays a role. In drier air, flakes tend to be flatter. More humid air usually causes more growth at the tips, corners and edges of snowflakes. Snowflakes can grow as more water molecules cluster together on the surface of the existing snow crystal or flake. The more water vapor there is, the more intricate and faster growing snowflakes can be.
Because snowflakes are so sensitive to temperature, they often change shape as they fall to the ground. As a result, it would be almost impossible for two snowflakes to experience the same conditions as they fall. This means it is virtually impossible for snowflakes to be identical.
It's widely accepted by researchers and scientists that no two snowflakes are alike, but that may only be true of the flakes on the ground.
At their earliest stages — when water vapor condenses around a dust particle and then crystallizes — snowflakes are simple, six-sided prisms. Most snowflakes will branch out, grow or merge with other flakes as they fall. However, it's possible a snowflake could retain its original shape if it stays in the same atmospheric conditions the entire time it falls to Earth.
If that were to happen, it's possible two snowflakes could be identical or at least nearly identical. But remember: 1 septillion snowflakes fall every winter, so the odds of finding a snowflake's perfect match are, as they say, slim to none.
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